AU603811B2 - Creación de Inventos y Patentes con Inteligencia Artificial

AU603811B2 – Improvements in electric motor shafts
– Google Patents

AU603811B2 – Improvements in electric motor shafts
– Google Patents
Improvements in electric motor shafts

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Publication number
AU603811B2

AU603811B2
AU75020/87A
AU7502087A
AU603811B2
AU 603811 B2
AU603811 B2
AU 603811B2
AU 75020/87 A
AU75020/87 A
AU 75020/87A
AU 7502087 A
AU7502087 A
AU 7502087A
AU 603811 B2
AU603811 B2
AU 603811B2
Authority
AU
Australia
Prior art keywords
rotor
electric motor
motor shaft
rotor assembly
shaft
Prior art date
1986-07-01
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Ceased

Application number
AU75020/87A
Other versions

AU7502087A
(en

Inventor
Peter Mcbratney
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

FF Seeley Nominees Pty Ltd

Original Assignee
FF Seeley Nominees Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1986-07-01
Filing date
1987-07-01
Publication date
1990-11-29

1987-07-01
Application filed by FF Seeley Nominees Pty Ltd
filed
Critical
FF Seeley Nominees Pty Ltd

1987-07-01
Priority to AU75020/87A
priority
Critical
patent/AU603811B2/en

1988-01-07
Publication of AU7502087A
publication
Critical
patent/AU7502087A/en

1990-11-29
Application granted
granted
Critical

1990-11-29
Publication of AU603811B2
publication
Critical
patent/AU603811B2/en

2007-07-01
Anticipated expiration
legal-status
Critical

Status
Ceased
legal-status
Critical
Current

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Classifications

H—ELECTRICITY

H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER

H02K—DYNAMO-ELECTRIC MACHINES

H02K1/00—Details of the magnetic circuit

H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction

H02K1/22—Rotating parts of the magnetic circuit

H02K1/28—Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures

Description

1111125 11114 1.6 -,AXM’AnisNdONW1)lrIHs) 9aIDV id OL W j.25~ 11111 1.
F
C ,V 7Form 10 COM NWEAL-Tlr OF AUSTRALIA ‘PAE00381195-6 PATENT AC 392-~ ETE SPECIFICATION FOR OFFICE USE: Application Number Lodged-, Class Int. Class Complete Specification Lodged: Accepted: Published: Priority: Relatg;d Art: 7ETM TO YALU 7 L MAIL.OFCR LODGED AT SUB-OFFICE
IC~
Adelcide/ This docurincit coatains the It ntt:de Uv11. I ~n4)ais eocvr;,c1 ur Name of Applicant AodI’ess of Applicant-, ActUal~loventor: Address for Service: TO BE COMPLETED BY APPLICANT F.F. SEELEY NOMINEES PTY. LTD.
3 Rothesay Avenue, St. Marys, State of South Australia, Commonwealth of Australia Peter McBRATNEY care of R.K. MADDERN ASSOCIATES, 345 King William Street, Adelaide, South Australia, 5000.
Complete Specification for the Invention entitled: «IMPROVEMENTS IN ELECTRIC MOTOR SHAFTS» The following statement Is a full dest~rpton of this Invention, Including the best method of performing It known to RV. us.
I PU 411 it 11W 1~ This invention relates to an imr’roved electric motor shaft and rotor assembly, which is particularly useful in a small fractional horsepower electric motor of the squirrel cage type, but is also useful in motors of other types.
Almost invariably, electric motors have previously t ~been provided with separaLtely machined metal shafts, and while these are very successful under average conditions, problem can arise if the motors are used under very moist conditions, the problems usually being related to corrosion. Another difficulty which i sometimes encountered is that quite often the diameter of the projecting portion of the shaft exceeds the hole diameter within the rotor lamination stack of the motor, and it then becomes necessary to use sleeves or other devices. If for example an electric motor requires a fan or thrower disc, then the fan or thrower disc has previously been a sej r’ate part subsequently fitted with an assembly operation.
If, however, material is merely moulded into a central cavity of a rotor, shrinkage may cause the shaft to be’loose within the rotor. While this problem can occur with a die-cast metal shaft, it is very much more serious with a moulded polymeric material, which can have as much as six times the expansion rate Qf steel.
‘he main object of this invention is to proviLde satisfactory shaft and rotoc ass~embly for an eloctric motor whereby the above difficulties are at Itsast partially reduced when utilising a shaft of In-situ moulded matoriJl, and in one embodiment of this invention the invention is charaoterised in that *ome at least of the contiguous surfaces between tho shaft and rotor are interlocking surfaces whih 4fe 1i’ at least one of a radial and an axial 1 ia~r~ surfaces 1) T 4 /q converging towards the centLe of the rotor.
-2 While the moulded material can be die-cast metal, the 4nvention is such that it can alternatively be of mouldable polymeric material, and the interlocking surfaces can be provided with such a slope as to firmly retain the shaft to the motor notwithstanding temperature differences. The ahaft can (if required) be formed to have portions which are of larger diameter than the portion which extends through the rotor 1 and subsequent machining can be avoided in most instances.
By using a moulding process, the cost of an electric motor shaft can be considerably reduced, and there are fewer constraints on the shape which can be achieved.
hereunder in some detail with reference to, and are illustrated in, the accompanying drawings, in which: FIG. 1 is an elevational section through a rotor and shaft assembly according to a first embodiment, FIG. 2 is a cross-section taken on line 2-2 of FIG.
1, FIG. 3 is a cross-section, similar to FIG. 2, but according to a second embodiment, and FIG. 4 is a cross-section, similar to FIG. 1, but according to a third embodiment.
In each embodiment the rotor of an electric motor is of the squirrel cage type, having a rotor 10 which comprises a stack of laminations 11 of ferro-magnetic material joined together by electrically conductive but non-magnetic bars 12 extending between two squirrel cage rings 13.
In FIGs. 1 and 2, the rotor 10 contains a central shaft aperture 14 and a plurality of recesses surrounding the shaft aperture 14, the recesses 15 being part circular in cross-section as shown in FIG. 2, but -3 1 where the recess walls enter the central aperture, they converge towards the centre of the rotor Thereby when a polymeric shaft 11 is moulded in-situ in the rotor 10,lit firmly grips the converging aperture walls.
The polymeric shaft 17 extends through the rotor, in FIGs. 1 and 2, has cap ends 19 which are of larger S diameter than the rotor aperture, and at each projecting and, there is provided a «shoulder» 20 in order to provide a bearing thrust face.
The method of producing the shaft is to firstly -lamp the rotor within a die, close the die, and Injection mould a settable polymeric material (for example a glass filled nylon) which under the pressure imparted flows through the central shaft aperture of the rotor, and fills the die cavities. Other engineering plastics which can perform satisfactory service include «Vitrex Peek», a plastic sold by I.C.I. Australia Operations Pty. Ltd., Deer Park, Victoria, «Uktem» sold by General Electric Corp., Schenectady, New York, U.S.A., and «Noryl» GFN3 SE, a glass filled product generally available. The die cavities are not limited to include z’ simple thrower devices but may also include such configurations as shoulders, cooling fan impellers, or discoid type throwers. They can also include inwardly projecting portions which form non-circular flats on the periphery of the shaft, for example for the retention of pulleys.
FIG. 3 is a section similar to FIG. 2, but the recesses 23 which surround shaft 14 have flat sides which converge towards the rptor centre the convergence being such that, uon of the plastics materialA simultaneous Fetemwithi the recesses in a circumferential direction will nevertheless maintain a firm contact at the interface 4 -ZBl between the\inwardly converging aperture walls and the plastics material.
The above embodiments will be seen to employ «radial C lock», and that arrangement has the very consideraole advantage that the laminations 11 of the rotor can all t be identical in shape and size.
r C V r c .t However, in the third embodiment of FIG. 4, use o ~is made of an «axial lock», wherein the aperture walls at the end of aperture 14 converge in an axial direction towards the rotor centre Thieangle of convergence aill be a function of the length and radius c%A -mut. SWMX\\ -^ecncc t-tosrn s~0\c a~vv oind rotor under hotAconditions. Thus if length is ive times greater than the radius R, the tangent of ngle is one fifth, that is, tan A=0.2, or A=20 0
A
eing one half the included angle of convergence. Due zo the initial shrinkage upon moulding of the shaft, the interference at the interfaces is sufficient that a radial lock is not necessary in the third embodiment The identical principles also apply to the radial lock arrangements of FIGs. 1, 2 and 3, \hsace.o s Aconsideration of the above embodiment will indicate that a number of advantages besides the cost advantage are achieved by this invention, including prevention of corrosion, and snubbing of torsional or lateral vibration of the rotor.
5 V1V O

Claims (8)

1. An electric motor shaft and rotor assembly wherein the rotor comprises a stack of laminations and a central aperture therethrough, and the shaft comprises in-situ moulded material, characterised in that some at least of the contiguous surfaces between the shaft and rotor are interlocking surfaces which engage one another in at least one of a radial and an axial direction, said interlocking surfaces converging towards the centre of the rotor.

2. An electric motor shaft and rotor assembly according to claim 1 wherein said in-situ moulded material is a resin based plastics material. f I 0f toi 0P 9 t 00 00O~

3. An electric motor shaft and rotor assembly according to claim 1 or claim 2 wherein said rotor contains a central aperture surrounded by a plurality of radially extending slots, the walla which define the slots converging towards the centre of the rotor where they open into the central aperture. 94 0 04 04 0 44 9 94 4 1 0 44,i

4. An electric motor shaft and rotor assembly according to >oo, claim 1 or claim 2 wherein the wall ends of said central ISO iac aperture converge towards the centre of the rotor. 0,

5. An electric motor shaft and rotor assembly according to claim 4 wherein the included angle of convergence of the aperture walls is approximately it S

6. An electric motor shaft and rotor assembly substantially as hereinbefore described with reference to and as illustrated in FIGS. 1 and 2 of the S- 6 accompanying drawings.

7. An electric motor shaft and rotor assembly substantially as hereinbefore described with reference to and as illustrated in FIG. 3 of the accompanying drawings.

8. An electric motor shaft and rotor assembly substantially as hereinbefore described with reference to and as illustrated in FIG. 4 of the accompanying drawings. Dated this 1st day of July, 1987. F.F. SEELEY NOMINEES PTY. LTD. By their Patent Attorneys R.K. MADDERN ASSOCIATES -7-

AU75020/87A
1986-07-01
1987-07-01
Improvements in electric motor shafts

Ceased

AU603811B2
(en)

Priority Applications (1)

Application Number
Priority Date
Filing Date
Title

AU75020/87A

AU603811B2
(en)

1986-07-01
1987-07-01
Improvements in electric motor shafts

Applications Claiming Priority (3)

Application Number
Priority Date
Filing Date
Title

AUPH667786

1986-07-01

AUPH6677

1986-07-01

AU75020/87A

AU603811B2
(en)

1986-07-01
1987-07-01
Improvements in electric motor shafts

Publications (2)

Publication Number
Publication Date

AU7502087A

AU7502087A
(en)

1988-01-07

AU603811B2
true

AU603811B2
(en)

1990-11-29

Family
ID=25637786
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

AU75020/87A
Ceased

AU603811B2
(en)

1986-07-01
1987-07-01
Improvements in electric motor shafts

Country Status (1)

Country
Link

AU
(1)

AU603811B2
(en)

Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

AU642354B2
(en)

1991-08-29
1993-10-14
Mitsubishi Denki Kabushiki Kaisha
Armature of DC motor

Citations (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

AU2158870A
(en)

1969-12-12
1972-05-04

Controls Company Of America

ROTOR SHAFT ASSEMBLY FORA DYNAMO-ELECTRIC MACHINE AND METHOD OF ASSEMBLING SAMET’i X

US4376254A
(en)

1981-06-10
1983-03-08

General Motors Corporation

Annular molded article secured to a shaft

1987

1987-07-01
AU
AU75020/87A
patent/AU603811B2/en
not_active
Ceased

Patent Citations (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

AU2158870A
(en)

1969-12-12
1972-05-04
Controls Company Of America
ROTOR SHAFT ASSEMBLY FORA DYNAMO-ELECTRIC MACHINE AND METHOD OF ASSEMBLING SAMET’i X

US4376254A
(en)

1981-06-10
1983-03-08
General Motors Corporation
Annular molded article secured to a shaft

Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

AU642354B2
(en)

1991-08-29
1993-10-14
Mitsubishi Denki Kabushiki Kaisha
Armature of DC motor

Also Published As

Publication number
Publication date

AU7502087A
(en)

1988-01-07

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